Practice with flashcards. Fourth grade students need to memorize geometric shapes, measurement equivalents and Roman numerals. Write the shape or problem on one side of the card and the answer on the back. Go through the cards with your child until he instantly recites the correct answer. Buy premade flashcards or make your own with index cards. There are also free online flashcards available on some websites.
Practice in situations involving real-life math. To familiarize your child with fractions, have her assist with doubling or halving recipes in the kitchen. For example, have your child measure out all the ingredients for chocolate chip cookies. If the recipe calls for 3/4 cup of sugar, have her calculate how much sugar you will need to double the recipe. Repeat with all ingredients.
Give your child an allowance. Turn an allowance into a learning experience by having your child determine how long it will take him to save up for something that he wants. Practice your child's consumer math skills by having him figure out how much change he should receive after making a purchase.
Play number games with your child. Board games, such as Yahtzee or Racko, are good at reinforcing addition and multiplication facts. Children in fourth grade need to be comfortable with adding and subtracting multiple-digit figures. Games with dice can also help a child practice math skills.
Take practice quizzes online. There are a number of websites that provide math support. You can practice online or print out quizzes and tests to administer to your child at home.